LASER INTERFEROMETER GRAVITATIONAL WAVE OBSERVATORY
LIGO Laboratory / LIGO Scientific Collaboration
LIGO- E1200632-v4
Advanced LIGO
9/4/2013
TwinCAT Library for the
ALS Laser
Alexa Staley, Daniel Sigg
Distribution of this document:
LIGO Scientific Collaboration
This is an internal working note
of the LIGO Laboratory.
California Institute of Technology
LIGO Project – MS 18-34
1200 E. California Blvd.
Pasadena, CA 91125
Phone (626) 395-2129
Fax (626) 304-9834
E-mail: info@ligo.caltech.edu
Massachusetts Institute of Technology
LIGO Project – NW22-295
185 Albany St
Cambridge, MA 02139
Phone (617) 253-4824
Fax (617) 253-7014
E-mail: info@ligo.mit.edu
LIGO Hanford Observatory
P.O. Box 159
Richland WA 99352
Phone 509-372-8106
Fax 509-372-8137
LIGO Livingston Observatory
P.O. Box 940
Livingston, LA 70754
Phone 225-686-3100
Fax 225-686-7189
http://www.ligo.caltech.edu/
LIGO
LIGO-E1200632-v4
Library
Title
ALSLaser
Version
4
TwinCAT version
2.11
Name space
–
Author
Alexa Staley, Daniel Sigg
Description
Monitors the ALS Laser
Controls the crystal and doubler temperature
A slow feedback servo is implemented to offload the fast PZT feedback
to the slow temperature controls. It implements the following equation:
𝑢𝑢 = (1 − ℎ) × 𝑢𝑢−1 + 𝑢𝑢 × (ℎ − 𝑢)
Or if the polarity is false:
𝑢𝑢 = (1 − ℎ) × 𝑢𝑢−1 + 𝑢𝑢 × (ℎ + 𝑢)
with
𝑢 = 𝑢𝑢𝑢𝑢𝑢 ∆𝑢 and ℎ = 𝑢𝑢𝑢𝑢 ∆𝑢.
∆𝑢: sampling interval,
𝑢𝑢𝑢𝑢 : unity gain frequency of integrator,
𝑢𝑢𝑢 : Knee frequency of proportional gain.
(only used for control of the laser crystal, not the doubler)
Error codes
0x0001 – Safety interlock engaged
0x0002 – Laser diode 1 guard alarm
0x0004 – Laser diode 2 guard alarm
0x0008 – Laser diode 1 current out-of-range
0x0010 – Laser diode 2 current out-of-range
0x0020 – Laser crystal TEC error signal out-of-range
0x0040 – Doubler crystal TEC error signal out-of-range
0x0080 – Laser diode 1 TEC error signal out-of-range
0x0100 – Laser diode 2 TEC error signal out-of-range
0x0200 – Noise eater readback signal out-of-range
0x0400 – Unity gain frequency too high
0x0800 – Proportional gain knee frequency too high
0x1000 – Temperature feedback limit exceeded
Library dependencies
ReadADC, WriteADC, SaveRestore, Error
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LIGO-E1200632-v4
Hardware Input Type
TYPE ALSLaserInStruct :
STRUCT
LaserDiode1PowerMonitor:
LaserDiode2PowerMonitor:
LaserCrystalTECErrorSignal:
DoublingCrystalTECErrorSignal:
LaserDiode1TECErrorSignal:
LaserDiode2TECErrorSignal:
NoiseEaterMonitor:
LaserDiode1TempGuard:
LaserDiode2TempGuard:
InterLock:
END_STRUCT
END_TYPE
INT;
INT;
INT;
INT;
INT;
INT;
INT;
BOOL;
BOOL;
BOOL;
Type name
ALSLaserInStruct
Description
Structure of the hardware input that are wired up for the ALS laser
Definition
STRUCT
Element
Name: LaserDiode1PowerMonitor
Type: INT
Description: Laser diode 1 power monitor
Element
Name: LaserDiode2PowerMonitor
Type: INT
Description: Laser diode 2 power monitor
Element
Name: LaserCrystalTECErrorSignal
Type: INT
Description: Laser crystal, TEC error signal
Element
Name: DoublingCrystalTECErrorSignal
Type: INT
Description: Doubling crystal, TEC error signal
Element
Name: LaserDiode1TECErrorSignal
Type: INT
Description: Laser diode 1, TEC error signal
Element
Name: LaserDiode2TECErrorSignal
Type: INT
Description: Laser diode 2, TEC error signal
Element
Name: NoiseEaterMonitor
Type: INT
Description: Noise eater monitor
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LIGO-E1200632-v4
Element
Name: LaserDiode1TempGuard
Type: BOOL
Description: Laser diode 1, temp guard
Element
Name: LaserDiode2TempGuard
Type: BOOL
Description: Laser diode 2, temp guard
Element
Name: InterLock
Type: BOOL
Description: InterLock
Hardware Output Type
TYPE ALSLaserOutStruct :
STRUCT
CrystalTemperature:
DoublerTemperature:
END_STRUCT
END_TYPE
INT;
INT;
Type name
ALSLaserOutStruct
Description
Structure of the hardware output that are wired up for the ALS laser
Definition
STRUCT
Element
Name: CrystalTemperature
Type: INT
Description: Crystal Temperature
Element
Name: DoublerTemperature
Type: INT
Description: Doubler Temperature
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LIGO
LIGO-E1200632-v4
User Interface Type
TYPE ALSLaserFrequencyControlsStruct:
STRUCT
On:
Enabled:
Run:
Reset:
Low:
High:
Range:
Ugf:
Pf:
Polarity:
END_STRUCT
END_TYPE
BOOL;
BOOL;
BOOL;
BOOL;
LREAL;
LREAL;
BOOL;
LREAL;
LREAL;
BOOL;
Type name
ALSLaserFrequencyControlsStruct
Description
Structure used in the user interface that are used for the slow
temperature controls
Definition
STRUCT
In/out Tag
Name: On
Type: BOOL
Description: On/Off button for temperature feedback
Output Tag
Name: Enabled
Type: BOOL
Description: Enabled by the autolocker
Output Tag
Name: Run
Type: BOOL
Description: Servo is running
In/out Tag
Name: Reset
Type: BOOL
Description: Reset the integrator and zero the output
In/out Tag
Name: Low
Type: LREAL
Description: Low limit for feedback controls in Hz
In/out Tag
Name: High
Type: LREAL
Description: High limit for feedback controls in Hz
Output Tag
Name: Range
Type: BOOL
Description: Feedback controls exceeds range
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LIGO-E1200632-v4
In/out Tag
Name: Ugf
Type: LREAL
Description: Unity gain frequency of temperature servo in Hz
In/out Tag
Name: Pf
Type: LREAL
Description: Knee frequency of proportional feedback in Hz; zero is none
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LIGO-E1200632-v4
User Interface Type
TYPE ALSLaserStruct :
STRUCT
Error:
LaserDiode1PowerMonitor:
LaserDiode2PowerMonitor:
LaserDiodePowerNominal:
LaserDiodePowerTolerance:
LaserCrystalTECErrorSignal:
DoublingCrystalTECErrorSignal:
LaserDiode1TECErrorSignal:
LaserDiode2TECErrorSignal:
TECTolerance:
NoiseEaterMonitor:
NoiseEaterNominal:
NoiseEaterTolerance:
LaserDiode1TempGuard:
LaserDiode2TempGuard:
InterLock:
CrystalTemperature:
CrystalCalibration:
CrystalFrequency:
FrequencyControl:
PZTTuningCoefficient:
PZTFrequency:
DoublerTemperature:
END_STRUCT
END_TYPE
ErrorStruct;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
LREAL;
BOOL;
BOOL;
BOOL;
LREAL;
LREAL;
LREAL;
ALSLaserFrequencyControlsStruct;
LREAL;
LREAL;
LREAL;
Type name
ALSLaserStruct
Description
Structure of the user interface tags that are used to control the ALS
Laser
Definition
STRUCT
Output Tag
Name: Error
Type: ErrorStruct
Description: For error handler
Output Tag
Name: LaserDiode1PowerMonitor
Type: LREAL
Description: Laser diode 1 power monitor in A
Output Tag
Name: LaserDiode2PowerMonitor
Type: LREAL
Description: Laser diode 2 power monitor in A
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LIGO-E1200632-v4
Input Tag
Name: LaserDiodePowerNominal
Type: LREAL
Description: Laser diode power nominal in A
Input Tag
Name: LaserDiodePowerTolerance
Type: LREAL
Description: Laser diode power tolerance in A
Output Tag
Name: LaserCrystalTECErrorSignal
Type: LREAL
Description: Laser crystal, TEC error signal in C
Output Tag
Name: DoublingCrystalTECErrorSignal
Type: LREAL
Description: Doubling crystal, TEC error signal in C
Output Tag
Name: LaserDiode1TECErrorSignal
Type: LREAL
Description: Laser diode 1, TEC error signal in C
Output Tag
Name: LaserDiode2TECErrorSignal
Type: LREAL
Description: Laser diode 2, TEC error signal in C
Input Tag
Name: TECTolerance
Type: LREAL
Description: TEC error signal tolerance in C
Output Tag
Name: NoiseEaterMonitor
Type: LREAL
Description: Noise eater monitor in V
Input Tag
Name: NoiseEaterNominal
Type: LREAL
Description: Noise eater nominal value in V
Input Tag
Name: NoiseEaterTolerance
Type: LREAL
Description: Noise eater tolerance in V
Output Tag
Name: LaserDiode1TempGuard
Type: BOOL
Description: Laser diode 1, temp guard, high is alarm
Output Tag
Name: LaserDiode2TempGuard
Type: BOOL
Description: Laser diode 2, temp guard, high is alarm
Output Tag
Name: InterLock
Type: BOOL
Description: InterLock, high represent an interlock
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In/out Tag
Name: CrystalTemperature
Type: LREAL
Description: Crystal Temperature in C or V
Output Tag
Name: CrystalCalibration
Type: LREAL
Description: Crystal temperature coefficient at 1064nm in MHz/C;
nominal -3000 MHz/C
In/out Tag
Name: CrystalFrequency
Type: LREAL
Description: Laser frequency as set by crystal temperature in MHz;
updating the CrystalFrequency will update the CrystalTemperature and
vis versa
In/out Tag
Name: FrequencyControl
Type: ALSLaserFrequencyControlsStruct
Description: Controls parameters for slow temperature feedback network
Output Tag
Name: PZTTuningCoefficient
Type: LREAL
Description: PZT tuning coefficient at 1064nm in MHz/V; nominal
1.5 MHz/V
Output Tag
Name: PZTFrequency
Type: LREAL
Description: Laser frequency as set by the PZT actuator in MHz
Input Tag
Name: DoublerTemperature
Type: LREAL
Description: Doubler Temperature
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LIGO
LIGO-E1200632-v4
Function Block
FUNCTION_BLOCK ALSLaserFB
VAR_INPUT
Request:
SaveRestoreEnum;
ALSLaserIn:
ALSLaserInStruct;
ConstrolsEnable:
BOOL:= FALSE;
PZTVoltage:
LREAL := 0.0;
END_VAR
VAR_OUTPUT
ALSLaserOut:
ALSLaserOutStruct;
END_VAR
VAR_IN_OUT
ALSLaserInit:
ALSLaserStruct;
ALSLaser:
ALSLaserStruct;
END_VAR
Name
ALSLaserFB
Description
Monitors the ALS laser and computes the slow controls feedback
Input argument
Name: Request
Type: SaveRestoreEnum
Description: Request for save/restore/safemode or noop
Input argument
Name: ALSLaserIn
Type: ALSLaserInStruct
Description: Input hardware structure
Input argument
Name: ControlsEnable
Type: BOOL
Description: Enables the slow controls feedback
Default: FALSE
Input argument
Name: PZTVoltage
Type: LREAL
Description: PZT controls voltage in V (error signal for slow controls
feedback)
Default: 0
Output argument
Name: ALSLaserOut
Type: ALSLaserOutStruct
Description: Output hardware structure
In/out argument
Name: ALSLaser
Type: ALSLaserStruct
Description: User Interface structure
In/out argument
Name: ALSLaserInit
Type: ALSLaserStruct
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LIGO-E1200632-v4
Description: Save/restore variable in persistent memory
Visual
Name
ALSLaserVis
Description
Displays power monitors, TEC error signals, noise eater status,
crystal temperatures, slow temperature controls parameters, and
alarms for temperature guards, interlock and error.
Placeholder
Name: ALSLaser
Type: ALSLaserStruct
Description: ALS laser structure
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